1. Field of the Invention
This invention is directed toward a bicycle seat suspension device. The invention is more particularly directed toward a bicycle seat suspension device connectedly interposed between a bicycle seat and a bicycle frame. The invention is also directed toward a bicycle incorporating the bicycle seat suspension device.
2. Description of the Related Art Including Information Disclosed Under CFR .sctn..sctn. 1.97-1.99
Various types of bicycle seat suspension devices are known. Most of the known seat suspension devices employ resilient means such as a spring mounted between the seat and a seat post tube forming part of the frame of the bicycle. The spring can be mounted within the seat post tube as shown in U.S. Pat. No. 5,370,351 by way of example, or it can be mounted in a seat post extending down from the seat which seat post, in turn, is mounted in the seat post tube as shown in U.S. Pat. No. 5,382,039 by way of example. The spring can be combined with fluid damping means as shown by U.S. Pat. Nos. 568,593, 3,891,236 and 5,324,058 by way of example.
The known suspension devices have many disadvantages however and have not been widely used. The main disadvantage of known bicycle seat suspensions is that they have their angle of operation restricted to the direction of the seat post and the seat post tube in which the seat post is mounted. The angle of operation is defined as the angle, in the plane of the bicycle, of the operational travel of the suspension device. This angle of operation differs significantly from the direction of the shock generated when the rear wheel of a bicycle rides over bumps. The direction of the shock is upwardly and forwardly through the seat to the torso of the rider whereas the angle of operation of the known suspension devices is directed upwardly and rearwardly and thus the known suspension devices do not efficiently absorb the shock. Another disadvantage in having the known seat suspension devices mounted within the seat post or the seat post tube is that they are generally aligned with the direction of pedaling generated forces which forces can induce unwanted oscillations in the suspension device.
Known seat suspension devices also have relatively high coefficients of static friction. This causes them to transmit uncomfortable vibrations. In addition, the known suspension devices, particularly those employing springs, utilize relatively large amounts of kinetic friction in damping or shock absorption. The energy dissipated in the kinetic friction must be provided by the cyclist leaving less energy available for propulsion. This makes these suspension devices less acceptable for the cyclists.
Many of the known seat suspension devices are also difficult to install. Most can not be easily installed on existing bicycles without making extensive and expensive modifications to the bicycles. Most also cannot be easily be adjusted, when installed, to fit the weight of the rider using the suspension device. Many also are quite complex in construction and thus relatively expensive to purchase.